Watch Crash Course Biology Season 1 Episode 35 Online
- COUNTRIES: United States of America
- Subtitles: English
Hank veers away from human anatomy to teach us about the (mostly) single-celled organisms that make up two of the three taxonomic domains of life, and one of the four kingdoms: Archaea, Bacteria, and Protists. They are by far the most abundant organisms on Earth, and are our oldest, oddest relatives.